Hopping Robot Stutter-Jumping Saves Power

Hopping robots of the future could use a two-part stutter-jumping step to dramatically reduce the amount of energy they use. Taking a short hop before a big jump could allow spring-based “pogo-stick” robots to reduce their power consumption as much as ten-fold.

(Georgia Tech Assistant Professor Daniel Goldman (left) and Graduate Student Jeffrey Aguilar examine a simple robot built to the dynamics of jumping. The research could lead to reduced power consumption by hopping robots.)

The formula for the two-part jump was discovered by analyzing nearly 20,000 jumps made by a simple laboratory robot under a wide range of conditions.

“If we time things right, the robot can jump with a tenth of the power required to jump to the same height under other conditions,” said Daniel Goldman, an assistant professor in the School of Physics at the Georgia Institute of Technology. “In the stutter jumps, we can move the mass at a lower frequency to get off the ground. We achieve the same takeoff velocity as a conventional jump, but it is developed over a longer period of time with much less power.”

In his 1954 novel Lucky Star and the Oceans of Venus, Isaac Asimov writes about the hoppers:

Hoppers are probably the most grotesque forms of transportation ever invented. They consist of a curved body, just large enough to hold a man at the controls. There was a four-bladed rotor above and a single metal leg, rubber-tipped, below. It looked like some giant wading bird gone to sleep with one leg folded under its body. Lucky touched the leap knob and the hopper's leg retracted. Its body sank till it was scarcely seven feet from the ground while the leg moved up into the hollow tube that pierced the hopper just behind the control panel. The leg was released at the moment of maximum retraction with a loud click, and the hopper sprang thirty feet into the air...